Two projects concerned with dentures and a third relating occlusal force to periodontal destruction were completed during the report period. A project to evaluate forces and mobility simultaneously on a post core crown during function is currently underway. One of the denture studies measures the duration of denture-tissue compression during various periods of the day and the other measures jaw position during various masticatory functions and compares them to measurements of articulator settings. The periodontal destruction-occlusal force comparison study was performed in monkeys. Horizontal and vertical forces were telemetered from the mouth for later comparison to periodontal damage seen in histologic sections. The force-mobility study is being done in humans. It will provide information for comparing occlusal surface morphology alterations to the magnitude and direction of forces and mobility.